Bearing parametric analysis for fatigue damage

Wind turbine gearboxes are exposed to dynamic and time-varying loads, which affect the useful life of their components. In fact, some designers believe that fatigue is the dominant factor in gearbox projects. Thus, the next step in the gearbox down-scaling project is to down-scale the machine without modifying its fatigue damage level.

Bearing data — 3D scatter plot of tapered roller bearing parameters (blue dots) and its fitted polynomial (red dots), given by $C =k_1 D^2 + k_2 D B$ , where $C$ is the dynamic load rating, $D$ is the external diameter, $B$ is the thickness, and $k_1$ and $k_2$ are fitting parameters. All parameters are normalized for visualization purposes.

The research work associated with this project is still under development and has not been published yet. It involves analyzing some key parameters of rolling bearings, such as their dynamic load rating, and its relationship with bearing geometry. The dynamic load rating is one of the main factors for bearing selection and fatigue calculations and it is chosen as the main parameter for bearing scaling. Bearing parameters were obtained from KISSsoft and analyzed in MATLAB, showing reasonable agreement between data and fitting results as shown in the figure above.

I obtained a deeper understanding of complex machinery and its main components while working with gearboxes. The analyses at component level and at gearbox level gave me a better systematic view of the behavior of complex machinery. Load estimation and fatigue calculations for bearings and gears are now part of my skillset and can be useful while analyzing other types of machinery.

Geraldo F. de S. Rebouças